Multiple studies rely on adjoint sensitivity analysis [1]} and on the "wavemaker", the overlap between the direct and adjoint sensitivity modes, introduced by [2]} to derive appropriate sensor and actuator placement. [3]} used a computation of the wavemaker on a confined cylinder flow to lay their sensors used as feedback for a reinforcement-learning-trained policy. [4]} resorted to the wavemaker to optimally locate both sensors and actuators in a diffuser flow.
